Over the past 30 years, dramatic advances in the understanding of HIV infection and its therapy have transformed HIV into a highly treatable, chronic disease. With this evolution, critical questions have arisen about how basic research and clinical trials relate to clinical epidemiology and outcomes research, both in the U.S. and internationally. The goal of the Program for AIDS Clinical Research Training (PACRT), which has successfully trained leading HIV clinical investigators for the past 20 years, is to provide training in quantitative research methodologies with a focus on HIV clinical research to predoctoral PhD students and physicians at formative stages in their careers. This training has prepared both groups: to conduct clinical research of the highest quality and of direct relevance to the prevention and treatment of HIV infection. They will make important contributions to the scientific literature and successfully develop as independent investigators. In the next grant cycle, the PACRT candidates will receive two years of research training under the close supervision and mentorship of one or more of the 14 experienced program faculty members. Trainees will receive didactic training at Harvard School of Public Health or other Harvard University sites. Primary performance sites for the five post-doctoral fellows will be the Massachusetts General Hospital, Beth Israel Deaconess Medical Center, Brigham and Women's Hospital, Children's Hospital Boston and Harvard Medical School. The primary site for the two predoctoral fellows will be the Harvard School of Public Health. This program has three specific aims for its trainees: 1) To acquire a sufficient body of knowledge of quantitative methods to conduct independent research in: clinical epidemiology, clinical trials, cost-effectiveness analysis, outcomes research, and/or implementation science. 2) To foster the creation of important scientific contributions with the close and longitudinal mentorship of program faculty. 3) To develop a primary research focus and a broad understanding of the various aspects of HIV disease for novel interdisciplinary research. Relevance: PACRT has a clearly defined and unique direction among HIV T32 programs, with its focus on clinical outcomes research, and how that research interfaces with translational research, clinical trials, and health policy. This program will play a crucial role in training the next generation of highly successful investigators to address the complex issues arising today in HIV clinical research.